Bug 489830 - Make MediaListener's mNextListener assertion a non-fatal error to avoid crashing in the face of a listener that breaks nsIRequest's contract. r+sr=roc

--HG--
extra : rebase_source : d88fd679bbb532193782f75a8e0cbdff43e602f2

content/html/content/src/nsHTMLMediaElement.cpp

@@ -245,7 +245,10 @@ NS_IMETHODIMP nsHTMLMediaElement::MediaLoadListener::OnDataAvailable(nsIRequest*
                                                                        nsIInputStream* aStream, PRUint32 aOffset,
                                                                        PRUint32 aCount)
 {
-  NS_ABORT_IF_FALSE(mNextListener, "Must have a listener");
+  if (!mNextListener) {
+    NS_ERROR("Must have a chained listener; OnStartRequest should have canceled this request");
+    return NS_BINDING_ABORTED;
+  }
   return mNextListener->OnDataAvailable(aRequest, aContext, aStream, aOffset, aCount);
 }